1. Field of the Invention
This invention relates to an apparatus for feeding electric circuit elements, for example, chip-shaped elements, from a supply thereof.
2. Description of the Prior Art
A hybrid integrated circuit usually includes a circuit board on which chip-shaped electric circuit elements of various kinds are mounted for forming an electric circuit. The present applicant has proposed, for example, in the laid-open Japanese Patent Application identified as No. 151,434/1980, an apparatus for feeding electric circuit elements to be used in manufacturing such hybrid integrated circuits. Such proposed feeding apparatus includes a hopper for containing a supply of the electric circuit elements, capture means slidably inserted in a bore extending through the bottom of the hopper and having an axially hole through the capture means so that, when the hopper and capture means are subjected to relative reciprocal movement, the electric circuit elements in the hopper are captured, one at a time, by the hole of the capture means and are fed therethrough to a predetermined position outside of the hopper. In the foregoing apparatus, it is desirable that the hopper accommodate a large number of the circuit elements so as to reduce the frequency with which the supply of electric circuit elements has to be replenished. Thus, it is desirable to provide a large capacity hopper which, in the case of a cylindrical hopper having its axis directed vertically, involves providing the hopper with a large diameter and/or axially height. However, when it is desired to feed various kinds of electrical circuit elements in parallel at the same time, it is necessary to provide a corresponding number of hoppers for the respective kinds of circuit elements and, if the diameter of each hopper is increased for accommodating a large supply of the respective circuit elements therein, the feeding apparatus, as a whole, will require a correspondingly large planar space. On the other hand, if the axially height of each cylindrical hopper is increased so as to permit the latter to contain a large supply of the respective electric circuit elements without unduly increasing the planar space required for the feeding apparatus, then circuit elements disposed in the lower portion of the hopper will be substantially stressed by the weight of the large number of circuit elements positioned thereabove. In such case, there is the danger that circuit elements at the bottom of the hopper may be damaged as a result of the relative movements of the hopper and capture means while the circuit elements contacted by the capture means are subjected to the excessive weight of the electric circuit elements thereabove.
Further, if each hopper is made slender by decreasing its diameter in order to reduce the planar space required for the feeding apparatus, circuit elements within the hopper may interengage in such a way as to form bridges or jams across the hopper so that, as the capture means removes the circuit elements one at a time from the bottom of the hopper, a void or empty space may be created in the bottom portion of the hopper in the region of the capture means so that the feeding of electric circuit elements from the hopper will be interrupted or stopped.
Moreover, in the case of electric circuit elements of the type used for manufacturing hybrid integrated circuits, the outer surfaces thereof, with the exception of the electrode portions at the opposite ends, are coated with a resin. Since the bottom of the hopper of the previously mentioned proposed apparatus has a smooth conically concave surface, the resin coatings on the electric circuit elements can cause the latter to adhere to the bottom of the hopper and to each other in layers. Such adherence of the circuit elements to each and to the inner surface of the hopper bottom interferes with the smooth feeding of the circuit elements and prevents the feeding of the last of the circuit elements that may be contained in the hopper.